Trust in the LORD with all your heart, and lean not on your own understanding; in all your ways acknowledge Him, and He will make your paths straight.
These lines come from a father speaking to his son, one of many such talks that open the book of Proverbs. He is handing down what he has learned about living well. "Heart" meant the whole inner self, including the mind and will. "Straight paths" pictured a smooth, level road instead of a rough or twisting one.
Proverbs, chapter 3. A collection of short sayings about wise living, many of them linked to King Solomon.